箱体类零件是矿山机械设备中最重要的组成零件之一，其加工质量直接影响着整个机器的运行状况和工作性能，同轴度是箱体类零件主要的一项形位公差参数，对工件的使用性能有着直接的影响，通过对加工箱体类零件时同轴度误差产生的原因进行分析，得出了孔直线在水平面和垂直面上产生偏差的理论计算公式。 Box parts is one of the most important components of mining machinery and equipment, the processing quality of a direct impact on the operation of the entire machine performance and performance, coaxiality is a box-shaped parts of a major form of tolerance parameters, The performance of the workpiece has a direct impact on the processing of parts by the coaxiality error analysis of the reasons were drawn hole straight line in the horizontal and vertical deviation of the theoretical formula.